Developed by the Institute of Agricultural Engineering at the University of Hohenheim, Phoenix is a versatile and innovative machine that is able to precisely cut things such as weeds, or loosen soil between rows of plants with its 100-kg hoe.
However, unlike most other machinery for weeding crops, operation is controlled by a joystick. The hoe is slowly raised, Phoenix moves to the next position and lowers the accessory equipment again. An adjustable system is hidden on the back of the robot and powerful LINAK® actuators LA36 provide the automatic lifting and lowering.
Free movement and full functionality throughout the day
The battery power covers a working day of eight hours. One of the three actuators LA36 is used for lifting (4,500 N), one for tilting (2,600 N) and one for lateral displacement (1,700 N) of the accessory equipment. All actuators are controlled via the CAN bus interface. At the end of the row of plants, Phoenix can lift and turn the working equipment independently, as well as react to changes, such as if the planting of the rows of plants is not straight. Thus, weeds can be removed on the crop.
Several benefits from going electric
For graduate engineer at the University of Hohenheim, David Reiser, there were many reasons for choosing electric actuators from LINAK for the project.
'The ratio between the vehicle weight and the actuator is correct. It is an electric, battery-powered vehicle. It was therefore not relevant to include hydraulics. Furthermore, the linear actuator offers a direct and linear adjustment'.
According to Reiser, a major advantage is the option of CAN bus control of the LINAK actuators. This is a requirement for the internal communication of the robot. The actuator is controlled by the CAN bus control and can move to a specific position. This gives the programmer more options and exact control over what the system does.
Furthermore, the millimetre range control of the actuators ensures that the accessory equipment can be controlled by an automatic change system. The required position data is determined using a stereo camera and a laser scanner and is transferred to the drive and electric actuators.
For Reiser and Hohenheim University, such future-oriented perspectives in agriculture can be implemented in practice and clearly conveyed to students with the Phoenix robot.
'Within the framework of bachelor and master's theses, research in the field of robotics can be carried out and innovative solutions can be developed. Thanks to the support from LINAK, the prototype of the movable frame was developed, and it has already been tested several times in practice,' says Reiser.
